Referring to FIG. 1, a lock 100 is usually disposed on a door for security or personnel access control, wherein the lock 100 includes an interior handle assembly 110, a latch assembly 120, an exterior handle assembly 130 and a retractor 140. A latch 121 of the latch assembly 120 is lodged into a door frame, an exterior handle 131 of the exterior handle assembly 130 is not able to drive the retractor 140 to drive the latch 121 of the latch assembly 120 in operation when a control button 111 of the interior handle assembly 110 is pressed or turned, and the lock 100 is locked.
Turn an interior handle 112 of the interior handle assembly 110 to restore the control button 111 and unlock the lock 100 when the door is intend to unlock.
Or, use a key 150 to drive a lock cylinder assembly 132 of the exterior handle assembly 130 to restore the control button 111 of the interior handle assembly 110 and unlock the lock 100.
Owing to the reason that the control button 111 of the interior handle assembly 110 must be pressed or turned before lock the door 100, so the exterior handle assembly 130 is not able to lock the door 100 when the control button 111 of the interior handle assembly 110 is not pressed or turned, therefore causes inconvenience of the user.